Question
TTOP Recitation Chapter 3 Fall 1. An object is launched from the origin with a velocity of 10.0 m/s at an angle of 30.0 degrees abowe velocity (magnitude and direction) of the object 2.0 seconds later? rizontal. (a) What is the initial velocity of the object in the (x) and (v) directions? (b) What is the 2. An airplane is flying horizontally at a speed of 50.0 m/s and at an elevation of 160 m drops a package. In order to hit a certain spot on the ground, how far before passing over the spot must he drop the package? 3. An object is launched from the origin with a velocity of 15.0 m/s at an angle of 30.0 degrees above the horizontal. What is the location (x and y) of the object 2.0s later? 4. An object is launched from the origin with a velocity of 45.0 m/s at an angle of 30.0 degrees above the horizontal. What is the range of the object? 5. A boat can move at 30 km/h in still water. How long will it take to go 12km upstream in a river flowing at 6.0 km/h?
Explanation / Answer
(4)
Given that
Velocity = 45 m/s
Angle = 30 degree
We know that
vx = 45 * cos(30)
= 38.97 m/s
vy = 45 * sin(30)
= 22.5 m/s
the time of travel is
t = 2*vy / g
= 2*22.5 / 9.8
= 4.59 s
The range is
D = vx * t
= 38.97 * 4.59
= 178.87 m
